This invention relates to a closure for a bottle. More particularly, this invention relates to a cap for a bottle, such as a milk bottle, which forms with the bottle an airtight seal to preserve the contents thereof. Once initially removed, the fact that the airtight seal has been broken as discernable from the cap yet the cap may be sealingly replaced on the bottle until the contents thereof are dissipated.
Most liquid containing bottles, particularly bottles containing consumable liquids, require tightly sealed closures thereon. Airtight seals are mandatory for certain liquids such as milk, carbonated beverages and certain medicines. In the milk industry, for example, to which this invention is primarily, but not exclusively, directed, numerous sealing methods have been developed over the years both for returnable and disposable bottles.
One early form of seal for a milk bottle consisted of a waxed disk which was forced within the bottle opening to act like a plug therein. A tab lifted from the disk was utilized to remove the same from the bottle. Such a closure was abandoned primarily because of numerous difficulties in lifting the tab from the disk thereby rendering the opening of the bottle a tedious task. This seal was replaced with the heavy paper seal which was attached to the bottle by crimping the perimeter of the same around the outer lip of the bottle. This closure was much easier to open but once opened, the bottle was poorly resealed since the closing effect of the crimping had been destroyed.
Most recently, primarily with the advent of disposable bottles, a threaded cap has bee utilized to engage a correspondingly threaded spout. A perforated plastic tear strip was utilized to seal the lowest point of the cap to the bottle to render the cap immovable and seal the contents of the bottle. Before one was able to turn the cap, the tear strip had to be cut and peeled away to thereafter permit rotation of the cap. Not only did the removal of the tear strip often prove tedious, but also the cost of manufacturing the threaded bottle and tear strip as well as installing the same became prohibitive.